Question: Express this product in scientific notation: $(2.00\times 10^{-4})\times (8.00\times 10^{-5})$
Explanation: Start by collecting like terms together. $= (2.00\times 8.00) \times (10^{-4}\times 10^{-5})$ When multiplying exponents with the same base, add the powers together. $= 16.0 \times 10^{-4\,+\,-5}$ $= 16.0 \times 10^{-9}$ To write the answer correctly in scientific notation, the first number needs to be between $1$ and $10$ . In this case, we need to move the decimal one position to the left without changing the value of our answer. $ $ We can use the fact that $16.0$ is the same as $1.600 \times 10$ $ = {1.600 \times 10} \times 10^{-9} $ $= 1.600\times 10^{-8}$